Solid catalyst component and catalyst for polymerization of olefins

ABSTRACT

The present invention provides a solid catalyst component for polymerization of olefins obtained by allowing a solid component and an alcohol to come in contact with each other, wherein the solid component is prepared by allowing a magnesium compound, a titanium compound and an electron donor compound to come in contact with each other, and also provides a catalyst for polymerization of olefins made of the solid catalyst component, an organic aluminum compound represented by the general formula R 1   p  AlQ 3-p  and an organic silicon compound represented by the general formula R 2   q  Si(OR 3 ) 4-q . By using the catalysts in a polymerization of olefins, polyolefins excellent in stereoregularity can be obtained in high yield.

TECHNICAL FIELD

The present invention relates to a solid catalyst component and catalystfor polymerization of olefins, which can provide a polymer having a highstereoregularity in a high yield.

TECHNICAL BACKGROUND

Many proposals have been made and known for a solid catalyst componentcontaining magnesium, titanium, an electron donor compound and halogenas essential components and a process for the polymerization orco-polymerization of olefins in the presence of a catalyst forpolymerization of olefins comprising said solid catalyst component, anorganic aluminum compound and an organic silicon compound. For example,JP-A-57-63310 and JP-A-57-63311 (The term "JP-A as used herein means an"unexamined published Japanese patent application") propose a processfor polymerizing an olefin having 3 or more carbon atoms using acatalyst system comprising a solid catalyst component containing amagnesium compound, a titanium compound and an electron donor compound,an organic aluminum compound and an organic silicon compound havingSi--O--C bond. However, these processes are not always satisfactory forobtaining highly stereoregular polymers in high yield, and furtherimprovement has been demanded.

On the other hand, JP-A-63-3010 discloses a catalyst system for thepolymerization of olefins and a process for polymerizing olefins usingthe same, the catalyst system comprising a solid catalyst componentprepared by bringing a dialkoxymagnesium, a diester of an aromaticcarboxylic acid, an aromatic hydrocarbon and a titanium halide intocontact and subjecting the resulting product in a powdered state to aheat treatment, an organic aluminum compound and an organic siliconcompound. JA-A-1-315406 discloses a catalyst system for polymerizingolefins comprising a solid catalyst component prepared by bringingtitanium tetrachloride with a suspension formed by diethoxymagnesiumwith an alkylbenzene, adding phthalic dichloride thereto to react toobtain a solid product, and further contacting the resulting solidproduct with titanium tetrachloride in the presence of an alkylbenzene,an organic aluminum compound and an organic silicon compound, and aprocess for polymerizing olefins in the presence of said catalystsystem. The foregoing known techniques focus on the development of acatalyst component having a high activity enough to allow the omissionof a so-called deashing step, i.e., step of removing catalyst residuessuch as chlorine and titanium remaining in the polymer produced as wellas on the enhancement of the yield of stereoregular polymer or animprovement in durability of the catalyst activity for polymerization,and achieved excellent results to these purposes.

The propylene polymer obtaining by using the forgoing catalysts,so-called a crystalline polypropylene, has a high rigidity and shows asuperior heat-resistability caused by having generally a highheat-deforming temperature, a high melting point and a highcrystallization temperature and is utilized in various uses, e.g., acontainer or a film other than a molded product of automobile orhousehold appliances.

In recent years, however, from the standpoint of energy saving orconservation of resources related to the global environmental issue, ithas been keenly desired to reduce the weight of plastics for use inautomobile, household appliance, etc. In order to solve this problem,the thickness of molded plastic articles needs to be reduced whilemaintaining its strength such as impact strength. Regarding polyolefins,to improve of rigidity of resin has been an important problem byimproving technology of compounding polymers and enhancing crystallinityof base polymer by polymerization technology, etc. in order to solvethese problems.

However, the foregoing known techniques are not enough to solve theproblems, and it is desired to develop a solid catalyst component forpolymerizing olefins or a catalyst system using the same which canenhance the stereoregularity or crystallinity of base polymer itself.

The present invention is intended to solve the foregoing problemsremaining in the prior art techniques. In other words, an object of thepresent invention is to provide a solid catalyst component and catalystfor polymerization of olefins, which can provide a superiorstereoregularity polymer in high yield.

DISCLOSURE OF THE INVENTION

As a result of extensive investigations to solve the foregoing problemsremaining in the prior art techniques, the present inventor has foundthat an olefin polymer having a high stereoregularity can be obtained inhigh yield by polymerizing an olefin(s) using a solid catalyst componentobtaining by contacting and reacting a solid component containingmagnesium, titanium, an electron donor compound and a halogen asessential components with an alcohol, or a catalyst comprising saidsolid catalyst component, an organoaluminium compound and an organicsilicon compound.

In other words, the present invention is a solid catalyst component (A)for polymerization of olefins, wherein the solid catalyst component isobtained by contacting a solid component containing magnesium, titanium,an electron donor compound and a halogen atom prepared by contacting amagnesium compound, a titanium compound and an electron donor compound,with an alcohol. Further, the present invention is also a catalyst forpolymerization of olefins, the catalyst comprising the foregoing solidcatalyst component (A), and the following components (B) and (C):

(B) An organoaluminium compound represented by the general formula (1):

    R.sup.1.sub.p AlQ.sub.3-p                                  (1)

wherein R¹ represents a C₁₋₄ alkyl group; Q represents a hydrogen orhalogen atom; and p represents a real number of from more than 0 to notmore than 3; and

(C) An organic silicon compound represented by the general formula (2):

    R.sup.2.sub.q Si(OR.sup.3).sub.4-q                         (2)

wherein R² represents a C₁₋₁₂ alkyl, cycloalkyl, phenyl, vinyl, allyl oraralkyl group which may be the same or different; R³ represents a C₁₋₄alkyl, cycloalkyl, phenyl, vinyl, allyl or aralkyl group which may bethe same or different; and q represents 0 or an integer of from 1 to 3.

BEST EMBODIMENT FOR IMPLEMENTING THE INVENTION

Preferred examples of the magnesium compound used for preparing a solidcomponent (a) (hereinafter occasionally referred to as "component (a)")constituting the solid catalyst component (A) for polymerization ofolefins of the present invention (hereinafter occasionally referred toas "component (A)") include magnesium dihalide, dialkylmagnesium,alkylmagnesium halide, dialkoxymagnesium, diaryloxymagnesium,alkoxymagnesium halide and fatty acid salt of magnesium, etc.

Examples of the magnesium dihalide include magnesium dichloride,magnesium dibromide, magnesium diiodide and magnesium difluoride, etc.

Preferred dialkyl magnesium is the compound represented by the generalformula R⁴ R⁵ Mg wherein R⁴ and R⁵ represent a C₁₋₁₀ alkyl group whichmay be the same or different. Specific examples of such dialkylmagnesiuminclude dimethylmagnesium, diethylmagnesium, methylethylmagnesium,dipropylmagnesium, methypropylmagnesium, ethylpropylmagnesium,dibutylmagnesium, methylbutylmagnesium and ethylbutylmagnesium, etc.Such dialkylmagnesium may be obtained by reacting magnesium metal withhalogenated hydrocarbon or alcohol.

Preferred alkyl magnesium halide is the compound represented by thegeneral formula R⁶ MgD¹ wherein R⁶ represents a C₁₋₁₀ alkyl group, D¹represents a halogen atom such as chlorine, bromine, iodine or fluorine.Specific examples of alkylmagnesium halide include ethylmagnesiumchloride, propylmagnesium chloride, butylmagnesium chloride, etc. Thesemagnesium halides may be obtained by reacting magnesium metal withhalogenated hydrocarbon or alcohol.

Preferred dialkoxymagnesium or diaryloxymagnesium is the compoundrepresented by the general formula Mg(OR⁷)(OR⁸) wherein R⁷ and R⁸ may bethe same or different and each represent a C₁₋₁₀ alkyl group or arylgroup. Specific examples of dialkoxymagnesium or diaryloxymagnesiuminclude dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium,dibutoxymagnesium, diphenoxymagnesium, ethoxymethoxymagnesium,ethoxypropoxymagnesium and butoxyethoxymagnesium, etc. Thesedialkoxymagnesium or diaryloxymagnesium may be obtained by reactingmagnesium metal with alcohol in the presence of a halogen or ahalogenated metal compound.

Preferred alkoxymagnesium halide is the compound represented by thegeneral formula Mg(OR⁹)D² wherein R⁹ represents a C₁₋₁₀ alkyl group andD² represents a halogen atom such as chlorine, bromine, iodine orfluorine. Specific examples of alkoxymagnesium halide includemethoxymagnesium chloride, ethoxymagnesium chloride, propoxymagnesiumchloride and butoxymagnesium chloride, etc.

Preferred fatty acid salt of magnesium is the compound represented bythe general formula Mg(R¹⁰ COO)₂ wherein R¹⁰ represents a C₁₋₂₀hydrocarbon group. Specific examples of the fatty acid salt of magnesiuminclude magnesium laurate, magnesium stearate, magnesium octanoate andmagnesium decanoate, etc.

Among these magnesium compounds in the present invention, thedialkoxymagnesium is used preferably. Particularly preferred among thesedialkoxymagnesiums is diethoxymagnesium or di-n-propoxymagnesium. Theforgoing magnesium compounds may be used singly or in combination of twoor more of them.

The dialkoxymagnesium may be used in granular or powder form to preparethe solid component (a) in the present invention. The particle shape ofthe dialkoxymagnesium may be amorphous or spherical. If a sphericalparticulate dialkoxymagnesium is used, a polymer powder having a betterparticle shape and a narrower particle size distribution can beobtained. Thus, the polymer powder produced can be easily handled duringthe polymerization, eliminating troubles such as blocking caused by thefine powder contained in the polymer powder produced.

The foregoing spherical particulate dialkoxymagnesium does notnecessarily need to be truly spherical but may be ellipsoidal orpebble-like. In some detail, the sphericity of the particle is normallynot more than 3, preferably from 1 to 2, more preferably from 1 to 1.5as calculated in terms of the ratio of major axis length l to minor axislength w (l/W). The process for preparing such spherical particulatedialkoxymagnesium is disclosed in JP-A-58-41832, JP-A-62-51633,JP-A-3-74341, JP-A-4-368391, and JP-A-8-73388.

Further, the foregoing dialkoxymagnesium may have an average particlediameter of normally from 1 μm to 200 μm, preferably from 5 μm to 150μm. The foregoing spherical particulate dialkoxymagnesium has an averageparticle diameter of normally from 1 μm to 100 μm, preferably from 5 μmto 50 μm, more preferably from 10 μm to 40 μm. Further, referring to itsparticle size, the foregoing spherical particulate compound preferablyhas a narrow particle size distribution comprising less fine or coarsepowder. In some detail, the particle size distribution comprisesparticles having a particle size of not more than 5 μm in an amount ofnot more than 20%, preferably not more than 10%, and particles having aparticle size of at least 100 μm in an amount of not more than 10%, morepreferably not more than 5%. The particle size distribution is not morethan 3, preferably not more than 2 as calculated in terms of ln(D90/D10) wherein D90 represents the particle diameter at the pointwhere the accumulated particle size reaches 90% and D10 represents theparticle diameter at the point where the accumulated particle sizereaches 10%.

Examples of the titanium compound to be used in the preparation of thesolid component (a) of the present invention is titanium halide andalkoxytitanium halide represented by the general formula Ti(OR¹¹)_(n)X_(4-n) wherein R¹¹ represents a C₁₋₄ alkyl group; X represents ahalogen atom such as chlorine, bromine and iodine; and n represents 0 oran integer of from 1 to 3. Further, the forgoing titanium compounds maybe used singly or in combination of two or more of them.

Specific examples of such a titanium compound include a titaniumtetrahalide such as TiCl₄, TiBr₄ and TiI₄, an alkoxytitanium halide suchas Ti(OCH₃)Cl₃, Ti(OC₂ H₅)Cl₃, Ti(OC₃ H₇)Cl₃, Ti(O--nC₄ H₉)Cl₃,Ti(OCH₃)₂ Cl₂, Ti(OC₂ H₅)₂ Cl₂, Ti(OC₃ H₇)₂ Cl₂, Ti(O--n--C₄ H₉)₂ Cl₂,Ti(OCH₃)₃ Cl, Ti(OC₂ H₅)₃ Cl, Ti(OC₃ H₇)₃ Cl, and Ti(O--n--C₄ H₉)₃ Cl.Preferred among these titanium compounds is titanium tetrahalide.Particularly preferred is TiCl₄. These titanium compounds may be usedsingly or in combination of two or more of them.

The electron donor compound, which can be used in the preparation of thesolid component (a) of the present invention, is an organic compoundcontaining oxygen or nitrogen. For instance, such compounds includealcohols, phenols, ethers, esters, ketones, acid halides, aldehydes,amines, amides, nitriles, isocyanates, and organic silicon compoundscontaining a Si--O--C bond.

Specific examples of the electron donor compound include alcohols suchas methanol, ethanol, n-propanol, and 2-ethylhexyl alcohol; phenols,such as phenol and cresol; ethers, such as dimethyl ether, diethylether, dipropyl ether, dibutyl ether, diamyl ether, and diphenyl ether;monocarboxylic acid esters, such as methyl formate, ethyl acetate, vinylacetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethylpropionate, ethyl butyrate, methyl benzoate, ethyl benzoate, propylbenzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenylbenzoate, methyl p-toluylate, ethyl p-toluylate, methyl anisate, andethyl anisate; dicarboxylic acid esters, such as diethyl maleate,dibutyl maleate, dimethyl adipate, diethyl adipate, dipropyl adipate,dibutyl adipate, diisodecyl adipate, dioctyl adipate, dimethylphthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate,dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctylphthalate, dinonyl phthalate, and didecyl phthalate; ketones, such asacetone, methyl ethyl ketone, methyl butyl ketone, acetophenone, andbezophenone; acid halides, such as phthalic acid dichloride andterephthalic acid dichloride; aldehydes, such as acetaldehyde,propionaldehyde, octylaldehyde, and benzaldehyde; amines, such asmethylamine, ethyl-amine, tributylamine, piperidine, aniline, andpyridine; amides, such as oleic acid amide and stearic acid amide;nitriles, such as acetonitrile, benzonitrile, and tolunitrile; andisocyanates, such as methyl isocyanate, and ethyl isocyanate.

Specific examples of the organic silicon compound containing a Si--O--Cbond are phenylalkoxysilane, alkylalkoxysilane, phenylalkylalkoxysilane,cycloalkylalkoxysilane and cycloalkylalkylalkoxysilane.

Among these electron donor compounds preferred are esters, with phthalicdiesters being more preferred. Specific examples of these phthalicdiesters include dimethyl phthalate, diethyl phthalate, di-n-propylphthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutylphthalate, ethylmethyl phthalate, methylisopropyl phthalate,ethyl-n-propyl phthalate, ethyl-n-butyl phthalate, di-n-pentylphthalate, diisopentyl phthalate, dihexyl phthalate, di-n-heptylphthalate, di-n-octyl phthalate, bis(2,2-dimethylhexyl) phthalate,bis(2-ethylhexyl) phthalate, di-n-nonyl phthalate, diiosdecyl phthalate,bis(2,2-dimethylheptyl) phthalate, n-butylisohexyl phthalate,n-butyl(2-ethylhexyl) phthalate, n-pentylhexyl phthalate,n-pentylisohexyl phthalate, isopentylheptyl phthalate,n-pentyl(2-ethylhexyl) phthalate, n-pentylisononyl phthalate,isopentyl(n-decyl) phthalate, n-pentylundecyl phthalate,isopentylisohexyl phthlate, n-hexyl(2-ethylhexyl) phthalate,n-hexylisononyl phthalate, n-hexyl-n-decyl phthalate,n-heptyl(2-ethylhexyl) phthalate, n-heptylisononyl phthalate,n-heptylneodecyl phthalate, and 2-ethylhexylisononyl phthalate. Thesephthalic acid esters may be used either individually or in combinationof two or more thereof.

Preferably, two or more diesters of phthalic acid may be used. Theircombination is preferably such that the difference between the sum ofthe number of carbon atoms contained in two alkyl groups in one phthalicacid ester and the sum of the number of carbon atoms contained in twoalkyl groups in another phthalic acid diester is at least 4.

In the preparation process of the solid component (a) of this invention,an aluminum compound, a metal salt of an organic acid or a polysiloxanemay be used other than the forgoing essential components.

Specific examples of the aluminum compound are aluminum trichloride,diethoxy aluminum chloride, diisopropoxy aluminum chloride, ethoxyaluminum dichloride, isopropoxy aluminum dichloride, buthoxy aluminumdichloride, triethoxy aluminum.

Specific examples of the metal salt of an organic acid are sodiumstearate, magnesium stearate and aluminum stearate.

As polysiloxanes there may be used one or more compounds represented bythe following general formula: ##STR1##

In the foregoing general formula, α represents an average polymerizationdegree of from 2 to 30,000. Most of R¹² to R¹⁹ each represents a methylgroup. A phenyl group, hydrogen atom, C₁₀₋₂₀ higher fatty acid residue,epoxy-containing group or C₁₋₁₀ polyoxyalkylene group may substitutesome of R¹² to R¹⁹. The compound represented by the forgoing generalformula may form a cyclic polysiloxane in which R¹⁵ and R¹⁶ are methylgroup.

The polysiloxane is known generically as silicone oil. It is a chain,partial hydrogenated, cyclic or denatured polysiloxane having aviscosity of from 2 to 10,000 cSt, preferably from 3 to 500 cSt, at 25°C. which stays liquid or viscous at room temperature.

Specific examples of the polysiloxane are dimethyl polysiloxane andmethyl phenyl polysiloxane as a chain polysiloxane, methyl hydrogenpolysiloxane of which the rate of hydrogenation is 10 to 80% as apartial hydrogenated polysiloxane, hexamethylcyclotrisiloxane,octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane,2,4,6-trimethylcyclotrisiloxane, and2,4,6,8-tetramethyl-cyclotetrasiloxane as a cyclic polysiloxane andhigher fatty acid-substituted dimethylsiloxane, epoxy-substituteddimethylsiloxane, and polyoxyalkylene-substituted dimethylsiloxane as adenatured polysiloxane.

The above-described solid component (a) can be prepared by contactingthe above-mentioned magnesium compound, titanium compound and electrondonor compound in a manner appropriately selected from conventionalmeans. Known methods for preparing a solid component are disclosed,e.g., in JP-A-63-308004, JP-A-63-314211, JP-A-64-6006, JP-A-64-14210,JP-A-64-43506, JP-A-63-3010, and JP-A-62-158704.

This contact can proceed in the absence of inert organic solvent butpreferably in the presence of inert organic solvent taking into accountthe ease of operation. Examples of the inert organic solvent employableherein include saturated hydrocarbon such as hexane, heptane andcyclohexane, aromatic hydrocarbon such as benzene, toluene, xylene andethylbenzene, and halogenated hydrocarbon such as orthodichlorobenzene,methylene chloride, carbon tetrachloride and dichloroethane. Inparticular, aromatic hydrocarbons of liquid state at a room temperaturehaving a boiling point of from about 90 to 150° C. are preferred.Specific examples of such aromatic hydrocarbons include toluene, xylene,and ethylbenzene.

Examples of methods for preparing the solid component (a) include themethod for obtaining a solid component by precipitating a solid matterby contacting an electron donor compound or an electron donor compoundand a titanium compound, or heat treatment with the solution of theforgoing magnesium compound dissolved in a alcohol or a titaniumcompound; and the method for obtaining a solid component by contactingand treating the suspension of a magnesium compound in a titaniumcompound or an inert hydrocarbon solvent with an electron donor compoundor an electron donor compound and a titanium compound. Among theabove-mentioned methods, the particles of the solid component obtainedby the former method is almost spherical and have a narrow particle sizedistribution. And, in the latter method, by using a spherical magnesiumcompound, the solid catalyst component having a spherical particle andnarrow particle size distribution can be obtained. Moreover, the solidcomponent having a spherical particle and narrow particle sizedistribution can be also obtained, for example, by forming a particle byso called a "spray-drying method" in which a solution or a suspension issprayed and dried by using a spraying apparatus.

The contact for each component is conducted under an atmosphere of aninert gas and a condition of eliminating water, etc. with stirring in avessel with agitator. The temperature for contacting can be set up atrelatively low temperature range of around room temperature in the caseof simply mixing with stirring after contacting or conducting adenatured treatment by dispersing or suspending. However, in the case ofobtaining a product by reacting after contacting, the temperature forcontacting is preferably at the temperature range from 40 to 130° C. Ifthe temperature at reaction is less than 40° C., such reaction is notproceeded completely and the efficiency of the resulting solid componentbecomes insufficient. If the temperature of the reaction exceeds 130°C., the reaction is hard to control because the solvent used in reactionvaporizes extremely. The time for reaction is usually 1 minute or more,preferably 10 minutes or more, more preferably, 30 minutes or more.

Typical methods for preparing solid component (a) are described below;

(1) Magnesium chloride is dissolved in a tetraalkoxy titanium, and thesolution is brought into contact with polysiloxane to obtain a solidproduct. The solid product is then allowed to react with titaniumtetrachloride, contacted with phthalic acid chloride, and allowed toreact with titanium tetrachloride to prepare solid component (a). Theresulting solid component (a) may be preliminarily treated with anorganic aluminum compound, an organosilicon compound, and an olefin.

(2) Anhydrous magnesium chloride and 2-ethylhexyl alcohol are reacted toform a uniform solution, which is then brought into contact withphthalic anhydride. The resulting solution is then brought into contactwith titanium tetrachloride and diester of phthalic acid to obtain asolid product, which is further brought into contact with titaniumtetrachloride to prepare solid component (a).

(3) Metallic magnesium, butyl chloride, and dibutyl ether are allowed toreact to synthesize an organomagnesium compound. The organo-magnesiumcompound is brought into contact with tetrabutoxy-titanium andtetraethoxysilane to obtain a solid product, which is then brought intocontact with a diester of phthalic acid, dibutyl ether, and titaniumtetrachloride to prepare solid component (a). The resulting solidcomponent may be preliminarily treated with an organic aluminumcompound, an organosilicon compound, and an olefin.

(4) An organomagnesium compound, e.g., dibutylmagnesium, and an organicaluminum compound are brought into contact with an alcohol, e.g.,butanol or 2-ethylhexyl alcohol, in the presence of a hydrocarbonsolvent to form a uniform solution. The resulting solution is broughtinto contact with a silicon compound, e.g., SiCl₄, HSiCl₃ orpolysiloxane, to obtain a solid product. The solid product is broughtinto contact with titanium tetrachloride and a diester of phthalic acidin the presence of an aromatic hydrocarbon solvent, and the reactionmixture is further brought into contact with titanium tetrachloride toobtain solid component (a).

(5) Magnesium chloride, a tetraalkoxytitanium, and an aliphatic alcoholare brought into contact in the presence of an aliphatic hydrocarbon toform a uniform solution. Titanium tetrachloride is then added to thesolution, and the mixture is heated to precipitate a solid product. Thesolid product is contacted with a diester of phthalic acid and furtheris allowed to react with titanium tetrachloride to prepare solidcomponent (a).

(6) Metallic magnesium powder, an alkyl monohalide, and iodine arecontacted. The resulting reaction product, a tetra-alkoxytitanium, anacid halide, and an aliphatic alcohol are contacted in the presence ofan aliphatic hydrocarbon to form a uniform solution. Titaniumtetrachloride is added to the solution, and the mixture is heated toprecipitate a solid component. The solid component is brought intocontact with a diester of phthalic acid and further reacted withtitanium tetrachloride to prepare solid component (a).

(7) Diethoxymagnesium is suspended in an alkylbenzene or a halogenatedhydrocarbon solvent, and the resulting suspension is brought intocontact with titanium tetrachloride. The mixture is heated and thencontacted with a diester of phthalic acid to obtain a solid product. Thesolid product is washed with an alkylbenzene and again contacted withtitanium tetrachloride in the presence of the alkylbenzene to preparesolid component (a). The resulting solid component may be subjected to aheat treatment in the presence or absence of a hydrocarbon solvent.

(8) Diethoxymagnesium is suspended in an alkylbenzene, and the resultingsuspension is brought into contact with titanium tetrachloride andphthalic acid chloride to obtain a solid product. The solid product iswashed with an alkylbenzene and again contacted with titaniumtetrachloride in the presence of the alkylbenzene to prepare solidcomponent (a). The resulting solid component may further be contactedwith titanium tetrachloride twice or more times.

(9) Diethoxymagnesium, calcium chloride, and a silicon compoundrepresented by Si(OR²⁰)₄ (wherein R²⁰ is an alkyl group or an aryl group) or co-ground, and the resulting grinds are suspended in an aromatichydrocarbon. The suspension is brought into contact with titaniumtetrachloride and an diester of phthalic acid, and the product isfurther contacted with titanium tetrachloride to prepare solid component(a).

(10) Diethoxymagnesium and a diester of phthalic acid are suspended inan alkylbenzene, and the suspension is added to titanium tetrachlorideto obtain a solid product. The solid product is washed with analkylbenzene, and further contacted with titanium tetrachloride in thepresence of the alkylbenzene to prepare solid component (a).

(11) A calcium halide and a fatty acid salt of magnesium, e.g.,magnesium stearate, are contacted and reacted with titaniumtetrachloride and an aromatic dicarboxylic acid diester, and thereaction product is further brought into contact with titaniumtetrachloride to prepare solid component (a).

(12) Diethoxymagnesium is suspended in an alkylbenzene or a halogenatedhydrocarbon solvent, and the resulting suspension is brought intocontact with titanium tetrachloride, and the mixture is heated andcontacted with a diester of phthalic acid to obtain a solid product. Theresulting solid product is washed with an alkylbenzene and furthercontacted with titanium tetrachloride in the presence of thealkylbenzene to prepare solid component (a). At any stage of the abovepreparation procedure, the system is brought into contact with aluminumchloride.

(13) Diethoxymagnesium is suspended in an alkylbenzene or a halogenatedhydrocarbon solvent, and the resulting suspension is brought intocontact with titanium tetrachloride, and the mixture is heated andcontacted with two or more diesters of phthalic acid different in thecarbon atom number of the alkyl moiety to obtain a solid product. Theresulting solid product is washed with an alkylbenzene and furthercontacted with titanium tetrachloride in the presence of thealkylbenzene to prepare solid component (a). In the above preparation,when the solid product is brought into contact with the second titaniumtetrachloride, it may again contacted with two or more diesters ofphthalic acid different in the carbon atom number of the alkyl group.And also, the above-mentioned electron donor compound other than thediesters of phthalic acid can be used with the diesters of phthalicacid.

(14) Diethoxymagnesium, titanium tetrachloride and a diester of phthalicacid are contacted and reacted with each other in the presence of chlorobenzene and the resulting product is brought into contact with titaniumtetrachloride and a phthalic acid dichloride and further contacted withtitanium tetrachloride to prepare solid component (a). The resultingsolid component may further be brought into contact with titaniumtetrachloride, and further, a silicon compound may be used in any stepof the forgoing contact or contacting reaction.

(15) Diethoxymagnesium, 2-ethylhexylalcohol and carbon dioxide arecontacted and reacted with each other in the presence of toluene toprepare a homogeneous solution, and the solution is further brought intocontact with titanium tetrachloride and a diester of phthalic acid toobtain a solid product, and further the solid product is dissolved intetrahydrofulan to precipitate a slid product. The solid productprecipitated is brought into contact with titanium tetrachloride and, ifnecessary, repeated the contact with titanium tetrachloride to preparesolid component (a). The silicon compound such as tetrabutoxysilane maybe used in any step of the forgoing contacting, reacting or dissolvingstep.

(16) Magnesium dichloride, an organic epoxy compound and a phosphoricacid compound are suspended in a hydrocarbon solvent such as toluene andheated to prepare a homogeneous solution. Phthalic anhydride andtitanium tetrachloride are contacted and reacted with the solution toobtain a solid product and a diester of phthalic acid is reacted withthe solid product. The resulting reaction product is washed with analkyl benzene and contacted again with titanium tetrachloride in thepresence of the alkyl benzene to prepare solid component (a).

(17) A dialkoxy magnesium, a titanium compound and a diester of anaromatic dicarboxylic acid are contacted and reacted each other in thepresence of toluene to obtain a solid product, and a silicon compoundsuch as a polysiloxane is contacted and reacted with the reactionproduct, and further contacted and reacted with titanium tetrachloride.The solid product is contacted and reacted with a metal salt of anorganic acid and contacted again with titanium tetrachloride to preparesolid component (a).

Preferred examples of the process for the preparation of the solidcomponent (a) used in the present invention will be given below:

A dialkoxymagnesium is suspended in an aromatic hydrocarbon compound,which states liquid at a room temperature to form a suspension. To thesuspension thus obtained is brought into contact with a tetravalenthalogenated titanium at -20 to 100° C., preferably -10 to 70° C., morepreferably 0 to 30° C. and reacted at 0 to 130° C., preferably 70 to120° C. In the procedure, before or after the suspension is brought intocontact with a halogenated titanium, one or two or more diester of anaromatic dicarboxylic acid is contacted at -20 to 130° C. to obtain asolid reaction product. The solid reaction product is washed with anaromatic hydrocarbon compound which states liquid at a room temperature,and brought into contact again with a tetravalent halogenated titaniumin the presence of an aromatic hydrocarbon compound at 0 to 130° C.,preferably 70 to 120° C., and further washed with a hydrocarbon compoundwhich states liquid at a room temperature to obtain solid component (a).The proportion of amount of each compound to be used is not specificallylimited because it is differed depending on the preparation method.Specific examples of the proportion of a tetravalent halogenatedtitanium is from 0.5 to 100 mols, preferably from 0.5 to 50 mols, morepreferably from 1 to 10 mols per mol of a dialkoxy magnesium. Theproportion of a diester of an aromatic dicarboxylic acid is from 0.01 to10 mols, preferably from 0.01 to 1 mol, more preferably from 0.02 to 0.6mol per mol of a dialkoxy magnesium.

The solid component (a) prepared above comprises magnesium, titanium, anelectron donor compound and a halogen atom. The content of eachcomponent is not specified, however, preferably the content of magnesiumis from 10 to 30% by weight, the content of titanium is from 1 to 5% byweight, the content of the electron donor compound is from 1 to 20% byweight and the content of the halogen atom is from 40 to 70% by weight.

In the present invention, the solid catalyst component (A) is preparedby contacting the solid component (a) prepared by the methodmentioned-above with an alcohol. In the procedure, the solid component(a) is necessary to contact with said alcohol after eliminating freetitanium in the solid component (a) by washing with a hydrocarbonsolvent. Specific examples of the method will be given below, althoughthe method for contacting with an alcohol is not specifically limited:

(1) Method of contacting the solid component (a) with a liquid alcohol;and

(2) Method of vaporizing an alcohol and contacting the solid component(a) with the vaporized alcohol.

In the procedure mentioned above, the solid component (a) may becontacted in the solid state, namely, powdery state or in the suspendedstate in a hydrocarbon compound which states liquid at a roomtemperature, specifically a saturated hydrocarbon compound such ashexane, heptane and cyclohexane. The alcohol may be used withoutdilution or used by diluting with a hydrocarbon compound, which statesliquid at a room temperature, specifically a saturated hydrocarboncompound such as hexane, heptane and cyclohexane. For example, asexplained in the preferable method for preparing a solid component (a)above, after the solid component is washed with a hydrocarbon whichstates liquid at a room temperature at several times, the solidcomponent (a) is suspended with the hydrocarbon by adding a freshhydrocarbon. An alcohol may be added to the suspension. Needless to saythat it is necessary to eliminate the free titanium in the suspensionefficiently in the procedure.

As an alcohol to be used for preparing the solid catalyst component (A),a mono or poly valent alcohol having 1 to 12 carbon atom may be used.Specific examples are momoalcols such as methanol, ethanol, n-propanol,iso-propanol, n-butanol, iso-butanol, s-butanol, t-butanol,n-amylalcohol, activated-amylalcohol, iso-amylalcohol, s-amylalcohol,3-pentanol, t-amylalcohol, n-hexanol, methyamylalcohol, 2-ethylbutanol,n-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-octanol,2-ethylhexanol, 3,5,5-trimethylhexanol, nonanol, n-decanol, undecanoland n-dodecanol, polyalcohols such as ethylene glycol, propylene glycol,trimethlene glycol, butandiol, 1,5-pentadiol, hexylene glycol, octyleneglycol, glycerine, 1,2,6-hexan triol, erythritol, pentaerythritol andhexytol. These alcohols may be used singly or in combination of two ormore of them.

An amount of an alcohol to be used is optionally as far as obtaining theeffect of the invention. Preferably, the amount of an alcohol is from0.005 to 10 mols, more preferably from 0.01 to 5 mols, particularlypreferably from 0.01 to 2 mols per mol of titanium atom in the solidcomponent (a). The temperature for contacting is from -20 to 120° C.,preferably from 0 to 100° C., more preferably from 10 to 80° C. and timefor contacting is 1 minute or more, preferably 10 minutes or more, morepreferably from 30 to 120 minutes.

Although the content of magnesium, titanium, an electron donor compoundand a halogen atom in the solid catalyst component (A) prepared above isnot specifically limited, the content of magnesium is prefeably from 10to 30% by weight, the content of titanium is preferably from 1 to 4% byweight, the content of the electron donor compound is preferably from 1to 20% by weight and the content of the halogen atom is preferably from40 to 70% by weight.

As the organic aluminum compound (B) to be used with the solid catalystcomponent (A) mentioned above to form a catalyst for polymerization ofolefins of the present invention, there may be used one represented bythe general formula: R¹ _(p) AlQ_(3-p) (in which R¹ represents a C₁₋₄-alkyl group; Q represents a hydrogen atom or halogen atom; and prepresents a real number of more than 0 to not more than 3). Specificexamples of the organic aluminum compound (B) include triethylaluminum,diethylaluminum chloride, tri-iso-butyl-aluminum, diethylaluminumbromide, and diethylaluminum hydride. These organic aluminum compoundsmay be used singly or in combination of two or more of them. Preferredamong these organic aluminum compounds are triethylaluminum, andtri-iso-butylaluminum.

As the organic silicon compound (C) to be used in the present inventionthere may be used a compound represented by the general formula R² _(q)Si(OR³)_(4-q), (in which R² may be the same or different and representsa C₁₋₁₂ -alkyl, cycloalkyl, phenyl, vinyl, allyl or aralkyl group; R³may be the same or different and represents a C₁₋₄ -alkyl, cycloalkyl,phenyl, vinyl, allyl or aralkyl group; and q represents 0 or an integerof from 1 to 3). Specific examples of the organic silicon compound (C)include phenylalkoxysilane, alkylalkoxysilane, phenylalkylalkoxysilane,cycloalkylalkoxysilane and cycloalkylalkylalkoxysilane.

Specific examples of the foregoing organic silicon compound includetrimethylmethoxysilane, trimethylethoxysilane,tri-n-propylmethoxysilane, tri-n-propylethoxysilane,tri-n-butylmethoxysilane, tri-iso-butylmethoxysilane,tri-t-butylmethoxysilane, tri-n-butylethoxysilane,tricyclohexylmethoxysilane, tricyclohexylethoxysilane,cyclohexyldimethylmethoxysilane, cyclohexyldiethylmethoxysilane,cyclohexyldiethylethoxysilane, dimethyldimethoxysilane,dimethyldiethoxysilane, di-n-propyldimethoxysilane,di-iso-propyldimethoxysilane, di-n-propyldiethoxysilane,di-iso-propyldiethoxysilane, di-n-butyldimethoxysilane,di-iso-butyldimethoxysilane, di-t-butyldimethoxysilane,di-n-butyldiethoxysilane, n-butylmethyldimethoxysilane,bis(2-ethylhexyl)dimethoxysilane, bis(2-ethylhexyl)diethoxysilane,dicyclohexyldimethoxysilane, dicyclohexyldiethoxysilane,dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane,bis(3-methylcyclohexyl)dimethoxysilane,bis-(4-methylcyclohexyl)dimethoxysilane,bis(3,5-dimethylcyclohexyl)dimethoxysilane,cyclohexylcyclopentyldimethoxysilane,cyclohexylcyclopentyldiethoxysilane,cyclohexylcyclopentyldipropoxysilane,3-methylcyclohexylcyclopentyldimethoxysilane,4-methylcyclohexylcyclopentyl-dimethoxysilane,3,5-dimethylcyclohexylcyclopentyldimethoxysilane,3-methylcyclohexylcyclohexyldimethoxysilane,4-methylcyclohexylcyclohexyldimethoxysilane,3,5-dimethylcyclohexylcyclohexyldimethoxysilane,cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane,cyclohexylethyldimethoxysilane, cyclohexyl(iso-propyl)dimethoxysilane,cyclohexylethyldiethoxysilane, cyclopentylmethyldimethoxysilane,cyclopentylmethyldiethoxysilane, cyclopentylethyldiethoxysilane,cyclopentyl(iso-propyl)dimethoxysilane,cyclohexyl(n-pentyl)dimethoxysilane, cyclohexyl(n-pentyl)diethoxysilane,cyclopentyl(iso-butyl)dimethoxysilane,cyclohexyl(n-propyl)dimethoxysilane, cyclohexyl(n-propyl)diethoxysilane,cyclohexyl(n-butyl)diethoxysilane, cyclohexyl(iso-butyl)dimethoxysilane,diphenyldimethoxysilane, diphenyldiethoxysilane,phenylmethyldimethoxysilane, phenylmethyldiethoxysilane,phenylethyldimethoxysilane, phenylethyldiethoxysilane,methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane,iso-propyltrimethoxysilane, iso-propyltriethoxysilane,n-butyltrimethoxysilane, iso-butyltrimethoxysilane,t-butyltrimethoxysilane, n-butyltriethoxysilane,2-ethylhexyltrimethoxysilane, 2-ethylhexyltriethoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane,phenyltriethoxysilane, tetramethoxysilane, tetraethoxysilane,tetrapropoxysilane and tetrabutoxysilane.

In the polymerization process of the present invention, thepolymerization of olefins is accomplished by the polymerization orcopolymerization of olefins in the presence of a catalyst made of theforegoing solid catalyst component (A), organic aluminum compound (B)and organic silicon compound (C). The ratio of the various components tobe used is arbitrary and not specifically limited unless the effects ofthe present invention are impaired. In general, the proportion of theorganic aluminum compound (B) is from 1 to 1,000 mols, preferably from50 to 800 mols per mol of titanium atom in the solid catalyst component(A). The proportion of the organic aluminum compound (C) is from 0.002to 10 mols, preferably from 0.01 to 2 mols, more preferably from 0.01 to0.5 mol per mol of the component (B).

The order of contact of each component is arbitrary. Preferably, organicaluminum compound (B) is charged first into a polymerization system, andthen brought into contact with organic silicon compound (C), and furthercontact with solid catalyst component (A).

The process for polymerization of the present invention may be carriedout in the presence or absence of an organic solvent. The olefin monomerto be polymerized may be used in either a gaseous state or a liquidstate. During the polymerization, hydrogen may be used as a molecularweight modifier. The polymerization temperature is not higher than 200°C., preferably not higher than 100° C. The polymerization pressure isnot higher than 10 MPa, preferably not higher than 5 MPa. The continuouspolymerization process or batchwise polymerization process may beapplied. Further, the polymerization reaction may be carried out in onestep or two or more steps.

The olefins to be homopolymerized or copolymerized by the process of thepresent invention include ethylene, propylene, 1-butene, 1-pentene,4-methyl-1-pentene and vinylcyclohexane. These olefins may be usedsingly or in combination of two or more of them. Among these olefins,ethylene and propylene are preferably used.

The polymerization (hereinafter referred as "main polymerization") ofolefins in the presence of the catalyst made of the foregoing solidcatalyst component (A), organic aluminum compound (B) and organicsilicon compound (C) is preferably preceded by prepolymerization tofurther enhance the catalytic activity and the stereoregularity,particle properties of the polymer thus produced and the like. As themonomers to be used in the prepolymerization there may be used the sameolefins as main polymerization as well as monomers such as styrene.

In the prepolymerization, the order of contact for each component andmonomer is arbitrary. Preferably, the organic aluminum compound (B) ischarged into the prepolymerization system set up to the atmosphere ofinert gas or olefin gas to be polymerized, and after contacting with thesolid catalyst component (A), brought into contact with one or moreolefins. In the case of conducting prepolymerization on combination withthe organic silicon compound (C), preferably, the organic aluminumcompound (B) is charged into the prepolymerization system set up to theatmosphere of inert gas or olefin gas to be polymerized, and aftercontacting with the organic silicon compound (C) and further the solidcatalyst component (A), brought into contact with one or more olefins.

In case that the polymerization of olefins is carried out in thepresence of the catalyst for polymerization of olefins formed by theinvention, the xylene solubles (XS) of polymer produced decrease 20% ormore in comparison with the polymer produced by a conventional method.Namely, it was confirmed the effect that a polymer having extremely highstereoregularity can be obtained in a high yield.

The present invention will be further described in the followingexamples as compared with the comparative examples.

EXAMPLE 1 Preparation of Solid Component (a)

Into a 2000-ml round flask equipped with an agitator in which had beenthoroughly replaced by nitrogen gas were charged 150 g ofdiethoxymagnesium and 750 ml of toluene to make a suspension. Thesuspension was then added to a solution of 450 ml of toluene and 300 mlof titanium tetrachloride pre-charged into a 3000-ml round flaskequipped with an agitator in which had been thoroughly replaced bynitrogen gas. To the suspension was then added 54 ml of di-n-butylphthalate and the suspension was heated to 110° C. On the way of suchheating, 60 ml of dimethylpolysiloxane was added thereto. Thetemperature of the reaction system was raised to 110° C. where thesuspension was then reacted for 2 hours. After the termination of thereaction, the resulting solid reaction product was then washed withtoluene. Thereafter, to the resulting solid reaction product were added1200 ml of toluene and 300 ml of titanium tetrachloride. The mixture wasthen processed with stirring at a temperature of 100° C. for 2 hours.Thereafter, the resulting solid reaction product was washed withn-heptane and separated by filtration and dried to obtain a powderedsolid component. The solid component was then measured for Ti content.The result was 1.41% by weight.

Preparation of Solid Catalyst Component (A)

Into a 500-ml round flask equipped with an agitator in which had beenthoroughly replaced by nitrogen gas were charged 10 g of the forgoingsolid component and 50 ml of heptane to make a suspension. To thesuspension was added the mixed solution adding 0.01 ml of ethanol in 50ml of heptane which was prepared previously. The mixture was reactedwith stirring at a temperature of 50° C. for 1 hour to obtain solidcatalyst component. The solid catalyst component was separated fromsuspension and then measured for Ti content. The result was 1.43% byweight.

Preparation of Polymerization Catalyst and Polymerization

Into a 2200 ml autoclave equipped with an agitator in which the airwithin had been completely replaced by nitrogen gas were charged theforegoing solid catalyst component in an amount of 0.0026 mmol ascalculated in terms of titanium atom, 1.3 mmol of triethylaluminum and0.13 mmol of cyclohexylmethyldimethoxysilane to form a polymerizationcatalyst. Into the autoclave were then charged 2000 ml of hydrogen gasand 1400 ml of liquid propylene. The mixture was then allowed to undergoprepolymerization at a temperature of 20° C. for 5 minutes and then mainpolymerization at a temperature of 70° C. for 1 hour.

Evaluation of Polymerization

On the polymer obtained by the forgoing polymerization, a polymerizationactivity per g of solid catalyst component (yield) and an amount ofpolymer undissolved when the polymer was extracted with boilingn-heptane for 6 hours (HI) were measured. The following equations (3)and (4) determined the polymerization activity and HI. Further, meltflow rate of the polymer produced (MI), bulk density (BD) and xylenesolubles (XS) were measured. XS was determined by the equation (5). Theresults of the forgoing measurements are set forth in Table 1.

    Yield(g-pp/g-cat.)=a (g)/solid catalyst component (g)      (3)

    HI (wt %)={b(g)/a(g)}×100                            (4)

    XS(wt %)={c(g)/a(g)}×100                             (5)

In the equations (3), (4) and (5) above, a shows a weight of polymerproduced after termination of polymerization reaction, b shows a weightof n-heptane undissolved polymer when polymer was extracted with boilingn-heptane for 6 hours and c shows a weight of polymer dissolving inp-xylene when polymer produced after termination of polymerizationreaction is dissolved with p-xylene at boiling point (about 138° C.) andthen cooled to 23° C.

EXAMPLE 2

The procedure of Example 1 was followed to effect the preparation of asolid component, the preparation of a solid catalyst component and theevaluation of polymerization in the presence thereof except that 0.02 mlof 2-ethylhexanol was used instead of ethanol. Ti content of theresulting solid catalyst component was 1.41% by weight. The results ofthe evaluation of polymerization are set forth in Table 1.

EXAMPLE 3

The procedure of Example 1 was followed to effect the preparation of asolid component, the preparation of a solid catalyst component and theevaluation of polymerization in the presence thereof except that 0.02 mlof ethylene glycol was used instead of ethanol. Ti content of theresulting solid catalyst component was 1.40% by weight. The results ofthe evaluation of polymerization are set forth in Table 1.

EXAMPLE 4

The procedure of Example 3 was followed to effect the preparation of asolid component, the preparation of a solid catalyst component and theevaluation of polymerization in the presence thereof except that theamount of solid component (a) to be used was 7.5 g. Ti content of theresulting solid catalyst component was 1.45% by weight. The results ofthe evaluation of polymerization are set forth in Table 1.

EXAMPLE 5

The procedure of Example 3 was followed to effect the preparation of asolid component, the preparation of a solid catalyst component and theevaluation of polymerization in the presence thereof except that theamount of solid component (a) to be used was 5.0 g. Ti content of theresulting solid catalyst component was 1.39% by weight. The results ofthe evaluation of polymerization are set forth in Table 1.

EXAMPLE 6

The procedure of Example 1 was followed to effect the preparation of asolid component, the preparation of a solid catalyst component and theevaluation of polymerization in the presence thereof except that 0.2 mlof glycerine was used instead of ethanol. Ti content of the resultingsolid catalyst component was 1.34% by weight. The results of theevaluation of polymerization are set forth in Table 1.

COMPARATIVE EXAMPLE 1

The procedure of Example 1 was followed to effect the preparation of asolid component and the evaluation of polymerization in the presencethereof except that the solid component (a) before contacting andtreating with alcohol was used instead of the solid catalyst component(A). The results of the evaluation of polymerization are set forth inTable 1.

                  TABLE 1                                                         ______________________________________                                               Yield           MI                                                            (g-PP/g-                                                                             HI       (g/10   BD     XS                                             cat)   (wt %)   min)    (g/ml) (wt %)                                  ______________________________________                                        Example 1                                                                              50,100   98.9     3.9   0.40   0.78                                  Example 2                                                                              47,500   99.0     4.9   0.40   0.74                                  Example 3                                                                              46,800   99.1     3.7   0.40   0.71                                  Example 4                                                                              50,600   98.9     3.2   0.40   0.68                                  Example 5                                                                              44,600   98.9     2.2   0.40   0.72                                  Example 6                                                                              45,900   99.2     2.7   0.40   0.69                                  Comparative                                                                            48,300   98.8     3.8   0.40   0.91                                  Example 1                                                                     ______________________________________                                    

Industrial Applicability

As mentioned above, the polymer having an extremely low xylene solubles(XS) and superior stereoregularity can be produced in high yield bypolymerizing olefins by using the polymerization catalyst of the presentinvention.

What is claimed is:
 1. A solid catalyst component for polymerization ofolefins, prepared by contacting a solid component comprising magnesium,a titanium halide, and an electron donor compound with an alcohol,wherein the solid component is prepared by contacting a magnesiumcompound with a titanium halide compound and an electron donor compoundin the presence of an aromatic hydrocarbon in the liquid state at roomtemperature.
 2. A solid catalyst component for polymerization of olefinsas in claim 1, wherein said solid catalyst component is prepared bycontacting a solid component with an alcohol after washing the solidcomponent with a hydrocarbon solvent.
 3. A solid catalyst component forpolymerization of olefins as in claim 1, wherein said alcohol is a monoor poly valent alcohol having 1 to 12 carbon atom.
 4. A solid catalystcomponent for polymerization of olefins as in claim 1, wherein saidalcohol is used in an amount of 0.005 to 10 mols per mol of titaniumatom in the solid component.
 5. A solid catalyst component forpolymerization of olefins as in claim 1, wherein said electron donorcompound is an ester of a mono carboxylic acid and/or an ester of adicarboxilic acid.
 6. A solid catalyst component for polymerization ofolefins as in claim 1, wherein said electron donor compound is a diesterof phthalic acid.
 7. A catalyst for polymerization of olefins, preparedfrom the following components (A), (B) and (C):(A) the solid catalystcomponent as defined in claim 1; (B) an organic aluminum compoundrepresented by the general formula (1):

    R.sup.1.sub.p AlQ.sub.3-p                                  ( 1)

wherein R¹ represents a C₁₋₄ -alkyl group; Q represents a hydrogen atomor a halogen atom; and p represents a real number of more than 0 to notmore than 3; and (C) an organic silicon compound represented by thegeneral formula (2):

    R.sup.2.sub.q Si(OR.sup.3).sub.4-q                         ( 2)

wherein R² may be the same or different and represents a C₁₋₁₂ -alkyl,cycloalkyl, phenyl, vinyl, allyl or aralkyl group; R³ may be the same ordifferent and represents a C₁₋₄ -alkyl, cycloalkyl, phenyl, vinyl, allylor aralkyl group; and q represents 0 or an integer of from 1 to
 3. 8. Asolid catalyst component for polymerization of olefins as in claim 1,wherein said aromatic hydrocarbon is toluene, xylene or ethylbenzene. 9.A solid catalyst component for polymerization of olefins as in claim 1,wherein said magnesium compound is a dialkoxymagnesium.
 10. A solidcatalyst component for polymerization of olefins as in claim 1, whereinsaid magnesium compound is diethoxymagnesium.